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Abstract:

A method and a system are disclosed for simulation in a substation. The
method can include acquiring substation data from substation condition
data and base substation record; adapting the acquired substation data to
suit a target substation; and administering the adapted substation data
on a communication channel of the target substation. The substation
system can include a base substation which is an existing, a pre
existing, or a target substation, or a substation defined by a user or
any combination thereof; a substation automation system; test equipment
configured to test the system and perform simulation in a target
substation; and a human machine interface for interfacing the substation
system with a user.

Claims:

1. A method for simulation in a substation, the method comprising:
acquiring substation data from substation condition data and base
substation record; adapting said acquired substation data to create
adapted substation data which will suit a target substation; and
administering the adapted substation data on a communication channel of
the target substation.

2. The method as claimed in claim 1, wherein the step of acquiring
substation data comprises: selecting substation condition data, a base
substation record, or both from one or more stored or retrieval computer
files from one of existing or pre-existing or target substations, from a
tool supported at least partially by a user, or from any combination
thereof.

3. The method as claimed in claim 1, wherein the adapting of the acquired
substation data comprises: mapping the acquired substation data for the
target substation, modifying the acquired or mapped substation data to
suit the target substation, or a combination of mapping and modifying.

4. The method as claimed in claim 3, wherein the mapping comprises:
mapping data of the base substation record with an identification
associated with corresponding data of the target substation.

5. The method as claimed in claim 3, wherein the modifying of the mapped
substation data comprises: constructing data for the target substation by
using or mathematically manipulating the acquired or mapped substation
data to suit the target substation.

6. The method as claimed in claim 3, wherein the modifying of the mapped
substation data comprises: incorporating the substation condition data.

7. The method as claimed in claim 1, wherein the administering of the
adapted substation data comprises: comparing the substation data in the
communication channel with a benchmark value or reference standards or
both; and validating the substation data in the communication channel for
target substation performance and functions.

8. A substation system comprising: a base substation, which is an
existing substation, a pre existing substation, a target substation, a
substation defined by a user, or any combination thereof; a substation
automation system; test equipment configured to test the substation
system and perform simulation in a target substation; and a human machine
interface for interfacing the substation system with a user.

9. The system as claimed in claim 8, wherein the test equipment
comprises: a library for storing data which includes substation condition
data, base substation record, mapped substation data, and/or modified
substation data, the test equipment being configured for performing one
or more of the following: capturing substation data from a communication
channel or recreating substation data from an IED or centralized
disturbance recorder, and storing the substation data; testing at least
one device's functionality, performance and interaction with plurality
device in the substation system; performing simulation of a substation
condition in the substation system; and performing simulation of a
substation condition in the substation system with simulation data from a
virtual substation.

10. The system as claimed in claim 9, wherein the communication channel
is a common communication channel based on an IEC 61850 communication
standard.

Description:

[0001] This application claims priority as a continuation application
under 35 U.S.C. §120 to PCT/IP2010/000582, which was filed as an
International Application on Mar. 19, 2010 designating the U.S., and
which claims priority to Indian Application 2213/CHE/2009 filed in India
on Sep. 14, 2009. The entire contents of these applications are hereby
incorporated by reference in their entireties.

FIELD

[0002] The present invention relates generally to the field of substation
automation and, for example, to a method and a system for simulation in a
substation.

BACKGROUND

[0003] Substations with high and medium voltage power networks can have
primary equipments such as power transformers, instrument transformers,
circuit breakers, switches, electrical cables, bus bars, incomers,
feeders, etc which are arranged in switch yards and/or bays. These
primary equipments are operated in an automated way by a Substation
Automation (SA) system. The SA system includes computer servers,
programmable devices called Intelligent Electronic Devices (IED),
engineering and operator stations (clients), communication network
connecting servers, IEDs and various clients on the network. The SA
system is primarily responsible for monitoring, control and protection of
substation equipments.

[0004] International Electrotechnical Committee (IEC) has introduced IEC
61850, now an internationally accepted communication standard for
communication between the devices of the substation automation. The
current SA systems are developed in conformance to such standards. The
IEC 61850 advocates interoperability amongst Intelligent Electronic
Devices (IEDs) from various manufacturers using common engineering
models, data formats and communication protocol. The adaptation of IEC
61850 for the industrial SA system allows effective use of SA system
tools for configuration and designing applications. The IEDs as referred
herein are devices which are compliant to such IEC 61850 standard.

[0005] In practice, substation and SA system can be tested during
commissioning, upgrading or maintenance of the substation or the SA
system. Substation and SA system together are referred as "the System" in
this discussion. The system is tested against power system conditions
relating to the substation in order to address operation reliability and
better predictability for a substation. In addition, there are other
tests related to connectivity, operation and performance of the SA system
carried out on the System.

[0006] It is recognized that the tests to simulate power system, power
system condition or to test an aspect related to SA system in the System
can be of enormous significance and are not trivial. In many cases, the
testing is done using highly expensive and bulky test equipment resulting
from the need to support analog connectivity to devices in the System or
to support multiple devices configured using multiple propriety
communication protocols. Often, such tests demand additional hardwiring
to be carried out involving SA system devices and substation equipment,
particularly in the System that is not completely IEC 61850 compliant.

[0007] In certain other cases, the tests are limited to operation of a
limited number, such as one device in connection with specific substation
equipment (e.g. an IED in connection with a circuit breaker). Such tests
can be carried out using relatively simpler test equipment, especially if
the device is a IEC 61850 compliant device. However, it is recognized
that tests on a System having multiple devices and equipment, such as for
a large substation, are complex. This is due to the effort to configure
the test equipment and draw inferences. The effort is mainly expended
towards configuring the test equipment: a) to recognize the substation
configuration and to communicate with each and every device/equipment
connected in the System; b) to execute the test plan reflecting operation
of one or more individual devices/equipment and capture interactions
among the various individual devices/equipment; and c) to test
performance and adequacy of supporting devices, for example devices
related to communication network (routers, network switches etc).

[0008] In the state of art, there is no test equipment that can
comprehensively test the System, or provide tests that are simple to
perform. The present disclosure describes methods and systems that can,
for example, provide such capabilities.

SUMMARY

[0009] Accordingly the present disclosure provides a method for simulation
in a substation. An exemplary method comprises: acquiring substation data
from substation condition data and base substation record; adapting the
acquired substation data to create adapted substation data which will
suit a target substation; and administering the adapted substation data
on a communication channel of the target substation.

[0010] The present disclosure also provides a substation system
comprising: a base substation which is an existing substation, a pre
existing substation, a target substation, a substation defined by a user,
or any combination thereof; a substation automation system; test
equipment configured to test the substation system and perform simulation
in a target substation; and a human machine interface for interfacing the
substation system with a user.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Exemplary embodiments will be discussed in detail with reference to
FIGS. 1 to 3 of the accompanying drawings, in which:

[0012] FIG. 1 shows a substation system according to an exemplary
embodiment;

[0013] FIGS. 2 and 3 show aspects related to configuration considered as
non exhaustive exemplary cases.

DETAILED DESCRIPTION

[0014] Exemplary embodiments will be explained for a System that is based
on the IEC 61850 standard. The IEC 61850 is an open communication
standard defining engineering models, data formats and communication
protocol that devices in the System may use for development and operation
of the System. The design and function of test equipment for simulation
in the substation system can rely on features resulting from adaptation
of IEC 61850 standard for the System.

[0015] An exemplary method and system are disclosed for easily performing
simulation in a substation.

[0016] Such a method and a system can reuse past events and substation
conditions for simulation in the substation.

[0017] The exemplary method and a system can address (e.g., ensure)
reliability in operation and predictability of the substation.

[0018] The exemplary method and system can perform simulation in a
substation device or in an entire system.

[0019] Further, the exemplary method and system are capable of performing
on-site simulation in a substation.

[0020] Exemplary test equipment as disclosed herein can include a
computer-based apparatus that has programmable features and executes test
and simulation programs involving the System. For example, a Personal
Computer, a laptop or a computer machine belonging to the System can be
configured in addition to functioning as test equipment. The test
equipment can be connected to an IEC 61850 based plant or process bus
(communication channel) in the System.

[0021] To test or perform a simulation, the test equipment can receive
data related to the substation layout along with various SA system
devices. In addition, information related to functionality of various
equipment/devices in the System, connectivity details, communication and
network information of the devices and equipment of the System can be
provided for comprehensively testing or simulation in the System. Most of
these data will be part of a SA system and available as one or more
configuration files. This data referred to as substation data are either
acquirable directly from the SA system or adaptable from similar data
related to any other System. The other System data is referred to as a
base substation record in this disclosure.

[0022] Therefore the test equipment should have capability to acquire as
much of information about the System under test from the SA system of the
System and adapt data as desired to carry out simulation/test. The
adaptation is also made from various base substation records available as
a library with the test equipment. The base substation record can contain
both substation information of a existing or pre-existing System (some
other substation existing elsewhere in the present or that of the past)
and also event/condition information that had occurred in the
existing/pre-existing System. The event/condition related information may
also be available as a separate information record (referred as a
substation condition data). It is to be noted that the substation
condition data is either available as a part of base substation record or
as a separate data record as another library with the test equipment.

[0023] The substation event/condition data can include both normal event
(example a merging unit publishing current and voltage sample values) and
abnormal event (fault condition arising because of malfunction of the
protection IED). As one would recognize, variety of normal and abnormal
events associated with various devices/equipment in the System are
possible. It is valuable to have functionalities in the test equipment to
test through simulation of various events for a new System or in the
System that has undergone any kind of change.

[0024] It is also to be recognized that an effective way to recreate
useful and relevant events for simulation for a System is through reuse
of as much as information as possible from the records (library). This
can reduce the effort to configure the test equipment to perform
simulation in the System. This also brings predictability in the System.

[0025] The IEC 61850 has well defined data formats that can be used to
communicate data for monitoring, control and protection. An IEC 61850
compliant Merging Unit in a substation system provides sampled and
digitized current and voltage data in the defined data format (IEC
61850-9-2). One would recognize that current and voltage information is
basic information connected with a condition of a substation, in general
any electrical network. Further, it is the voltage and current data that
can trigger various events in the substation. Therefore, in this
disclosure, as an exemplary illustration, merging unit data is being
treated as primary data to create and trigger various events for test
purposes in the substation under test. Henceforth, the substation under
test (the substation where simulations are performed) is referred as
target substation.

[0026] In FIG. 1, the System (100) is illustrated to include a test
equipment (150) connected to a digital communication channel (140) that
connects SA devices based on particular standards such IEC 61850. The
sampled voltage and current data can be provided by Merging Units
associated with the substation. However, to illustrate an exemplary
embodiment, the Merging Unit (130) associated with the System (or the
section of the System) is isolated and the test equipment (150) sends out
the sampled voltage and current (simulated) in the communication channel
(140) on the behalf of the Merging unit. The IED (120) would respond to
the voltage and current data sent out by the test equipment (150) in the
same manner as if the Merging Unit (130) indeed sent out the voltage and
current data communication.

[0027] It is re-iterated that in the System that is IEC 61850 compliant it
is adequate to send out digital information in the communication channel
in order to simulate an event or condition in the System. Here, the term
"condition" is used in generic sense to include both normal (operating)
condition and abnormal (fault) condition. The term `event` is used to
indicate an event of interest. An event could include (e.g., consist of)
one or more states of the System where the states change in a temporal
manner having a well defined cause and effect. It is to be noted that the
term `condition` in general can include multiple events belonging to
operating and fault conditions.

[0028] The test equipment (150) could easily take a role of one or more
devices such as MU (130) and simulate a particular condition, either
normal or abnormal condition in the System. It is to be noted that the
particular condition can be enacted (simulation) in the System (100) with
streams of data injected by the test equipment (150) into the System. The
test equipment (150) in addition to injection of data is also capable of
receiving all information that is sent out (published) in the
communication channel (140) to assess response of a particular device or
multiple devices including interactions between the multiple devices in
the System. Further, the test equipment (150) is also capable of adapting
(in programmed manner) based on published information in the
communication channel (140). In other words, the test equipment (150) is
capable of injecting data as a response to information received in the
communication channel (140).

[0029] The data published in the communication channel can be based on the
IEC 61850 data format containing multiple data frames that has both power
system information and the communication network information. In addition
to simulation related to power system condition, it is possible to design
a simulation to test communication network. The conditions related to
communication network simulation include both connectivity and
performance related tests by creating suitable events and by having
corresponding data generated in the System in command of the test
equipment (150). The data in the communication channel being the sampled
data can be correlated with some information such as quality, lost
samples etc. These contribute to the quality attributes and are
associated with the sampled data, which provides information to the
subscribed devices like IEDs to check whether the corresponding data can
perform its function. The test equipment when desired can be programmed
to analyze the quality information as well. This feature of the test
equipment allows comprehensive testing and simulation in the System.

[0030] As mentioned earlier, a condition is simulated through one or more
events in the System. The events can include one or more of hardware
equipment related events (configurations, functionality, performance),
power system related events, network related events, communication
related events (connectivity, protocols) etc. The events that are
simulated could be one or more depending upon the importance,
criticality, sufficiency, related effects etc. Examples of power system
related events include states related to protection, monitoring or
control functions in the substation. Examples of network related events
include occurrence and capture of unsupported packets, undetected source
sending data and corrupted packets in the communication channel.

[0031] The above paragraphs illustrate the general philosophy of an
exemplary embodiment explained through the features and scope of the test
equipment. An exemplary method to configure the test equipment to perform
simulation in the System is hereby described.

[0032] The test equipment can be provided with a library (160) of stored
substation data files. These files are specific to a particular
substation and are used as base files to configure test equipment for
simulation. The particular substation data therefore is referred to as
base substation data and the condition data related to the particular
substation is referred to more generically as substation condition data.
The substation condition data herein referenced includes conditions,
events and interactions related to a power system, substation devices and
equipment, communication system, and networks in the substation. Further,
the substation condition data is also derivable from one or more of the
data like substation failure mode data, fault tree data, state diagrams,
substation site acceptance test data, substation factory acceptance test
data, specifically designed test cases for substation verification and
validation. These events can be stored as XML files.

[0033] As mentioned earlier, the base substation data and substation data,
made available as records in a library can be records created from
existing or pre-existing substations. A new record may be freshly created
or a record from existing or pre-existing substation may be suitably
modified by an expert user with help of relevant engineering tools. As an
example, an instance of creating such a library record is provided
herewith. For instance, a problem in the merging unit or the
communication channel can result in losing the sampled data. This could
be treated as an event and captured and recorded along with its relevant
information and corresponding substation data for use as a record in the
library. Information on the position of the circuit breakers and
isolators and the substation configuration can also be stored in the
library.

[0034] The test equipment may be used as a device that captures events and
conditions in the substation either automatically or user initiated to
update its library. The records for library may come from any external
source or a global repository. The test equipment in turn may constantly
update the global repository if so configured. The user (180) can also
include information on how the System behaved for a given fault or a
problem and thereby provide an opinion on the same. These inputs can be
also stored in the library (160).

[0035] Power system information can be inferred with respect to the single
line diagram. The bay to which the devices in a substation are connected
and the associated devices are identified for instance, from information
corresponding to current and voltage channels represented as logical node
information present in the substation configuration information. The
substation configuration information from the target substation including
the single line diagram information, device and equipment information,
and communication network information can be gathered and used as
reference to configure the test equipment.

[0036] Relevant data pertaining to the target substation for use in test
and simulation is referred to as substation data. The substation data
mentioned here can be one or more of power system data, communication
data, network information, and data relating to substation, device,
equipment/components and configuration. The power system data refers to
data such as current, voltage, trip information, line diagram etc and can
be stored as COMTRADE (COMmon format for TRAnsient Data Exchange) files.
The communication data relate to data such as communication standard,
protocols, data packet information, data frame information and can be
stored as files in .ACP format, which is a format for network traffic
capture. The network information referenced here can relate to
information like MAC address, IP address, router information, data frame
information etc.

[0037] The action of performing the check is referenced as Meta analyses
and it can be done by comparing the substation data with tolerance
benchmarks or reference standards or a combination thereof.

[0038] In line with the foregoing, exemplary embodiments can further be
explained through non exhaustive exemplary cases. At the outset, testing
of a System with relevance to its commissioning is one such case under
consideration.

[0039] Owing to the above, commissioning of a System can involve various
stages, in which testing is one of the prime stage. The System which is
commissioned or to be commissioned is the target system. The testing here
is introduced either to test the System on-site or to simulate events in
a target System before actual commissioning is done. To perform this,
simulation of one or more events can be performed for which the data as
described herein before are involved. Though, the test system thrives on
use of base substation records from the library, it should be noted that
the data can also be obtained from the user which may form the entire
part of the data or a part thereof which is taken in conjunction with the
data made available as described herein. In an exemplary embodiment, a
base substation record that approximately resembles the target substation
schematics (line diagram) is selected from the library. Similarly, a
substation condition data is also selected from the library based on the
event that is desired for simulation. It is re-iterated here, that a base
substation record may include the events as well wherein the base
substation record selected is expected to approximately match the
schematics of the target substation and also possess the desired event
information.

[0040] Obtaining the substation condition data and the substation data
from the library for simulation of events is referred to as the acquiring
of data or data acquisition.

[0041] The data acquisition is followed by mapping the acquired data.
Mapping can be done by comparing the base substation data with that of
the target system. Considering a target substation schematic (300) as
shown in FIG. 3 having three feeders (320a, 320b and 320c) as compared
with the base substation schematic (200) as shown in FIG. 2, selected on
a basis of close resemblance having four feeders (220a, 220b, 220c and
220d) as a non exhaustive exemplary embodiment, an exemplary embodiment
can be explained further. In accordance to the same, a target substation
(300) of the target system as considered here has one feeder less
compared to the base substation (200) and all other features in the
schematics being identical. It is to be noted that the FIG. 2 and FIG. 3
embodiments are much simplified and most of the devices that normally are
present in the substation are not depicted in the figures. However, one
would recognize that Incomer, Feeders, Bus section and Bus coupler are
addressed as Bays and the various devices connected to a particular bay
along with information regarding merging unit can be easily retrieved
from the logical node information in the configuration files.

[0042] By observing the substation data and the ratings corresponding to
the base and target substation it can be decided which is the
corresponding feeder in the target substation which can be treated as
missing from the substation data made available from the base substation
record. Feeder information such as rating, sampling frequency etc may
also be used to identify the feeder that closely resembles the target
system. The base station record is suitably changed to match the
configuration of the target substation. Further, the base substation
record is changed to correspond to the target substation data. This is
referred to as a mapping step as all the device identities, network
identities of the target substation are mapped into the base station
record. At this stage, the base station record has all the configuration
and identity information of the target substation along with the event of
interest. This provides a data termed to be mapped substation data which
is further used in the context of the embodiment. Though, the
configuration and identity information are now mapped to suit the target
substation, the voltage and current sampled values present in the
substation condition data containing the event of interest should be
modified to correspond with that suitable for the target substation. This
is referred to as modification and is illustrated with help of FIG. 2 and
FIG. 3. FIG. 2 depicts a line diagram for a substation from the base
substation record and FIG. 3 depicts a line diagram of the target
substation.

[0043] In line with the foregoing embodiment, and as shown in FIG. 2, the
current value being the power system data of the substation data relates
to the base substation (200). The first phase currents of the respective
bays in the base substation having four bays are represented as IA1, IA2,
IA3, IA4, Ia1, Ia2, Ia3 and Ia4. On comparison of the line diagram from
the base substation record with the line diagram of the target
substation, it is evident that the target substation has one less feeder.
The incomers (210a, 210b), bus section (230), bus coupler (240), feeders
(220a, 220b, 220c), bus (250a, 250b, 250c) of the base substation (200)
are analogous to the incomers (310a, 310b), bus section (330), bus
coupler (340), feeders (320a, 320b, 320c), bus (350a, 350b, 350c) of the
target substation (300), respectively. The missing feeder in the target
substation (300), is referred to as the fourth feeder (220d) of the base
substation (200). Further, for this example, bus section (230) and bus
coupler (240) are considered as a closed condition in the base substation
(200) and the contribution of the current of fourth feeder (220d) is
subtracted vectorially from the incomers (210a, 210b) equally or in
factors as described below.

where `a` and `b` are less than 1 and depend on the incomers contribution
towards the missing feeder. If a=b, contributions are equally distributed
among the incomers (210a, 210b). Information on the position of circuit
breakers and switches in the base substation data also decides the
factors `a` and `b`. If the data of the missing feeder (220d) is in an
opened condition or corresponds to one which is connected to a dead bus
in the base substation data, then the contribution of that feeder need
not be considered. If the ratings of the bays in the base substation data
are different from that of target substation (300) then, IA1, IA2, IA3,
IA4, Ia1, Ia2, Ia3 can be multiplied by a factor. The factor as herein
described is represented as `X` which can be a ratio between the ratings
of the bay in the target substation (300) to the rating of the mapped bay
in the base substation (200).

[0044] The Factor `X` can also be decided by the user (180). The user
(180) can also map the data from the base substation to different feeders
by modifying them with respect to sampling frequency and rating, and also
adjusting the contribution through incomers, bus section and bus coupler
breakers.

[0045] Modifying the mapped substation data to constitute modified
substation data is done as described herein above so as to suit the
target substation and also to incorporate the substation condition data.
The modification of the mapped substation data can be done according to
the position of the breakers and isolators in different bays and this can
be extended to various positions of switches and configuration of the
substation. The newly made data (modified substation data) may be stored
in the library (160) as a new base substation record for future use.

[0046] A user can vary the direction of flow of current through the bus
section and bus coupler depending on each others position as well as the
feeder and incomer connection to the bus. This can be done in the
graphical single line representation of the target substation.
Accordingly, the distribution of current through the bus section and bus
couple breaker also varies. The user can thereby verify the substation
automation function of the target system for various positions of bus
coupler breakers and isolators.

[0047] The above example is an illustration of a power system condition.
However, it is to be noted that the base station records capture various
conditions in the substation (eg network related condition) for
simulation in the target system for studies with unsupported packets
received, undetected source sending data and corrupted packets. As
mentioned earlier, the base substation record can involve suitable
mapping and modification for simulation use in the target substation.
Network related or communication events would involve an appropriate
change made with regard to destination MAC/IP addresses. The change may
be carried out automatically through suitable algorithms to update MAC
addresses (source and destination within the target substation) to make
the data suitable for simulation in the target substation network.
Automatic computation and modifications for power system data may also be
performed.

[0048] The user (180) can select from the library (160), different types
of fault conditions, which have occurred in a bay or only that substation
data corresponding to the bay of the base substation or a combination of
such bay data of the base substation with relevant information for
mapping and can be used in mapping with the target substation and other
bay data can be modified accordingly. This proves to be an effective way
of reusing the already available data for performing the simulation.

[0049] The modified substation data is applied on the common communication
channel (140) after converting the modified substation data to
communication and network data. Further, the applied data serves to
create normal or fault conditions for test in the target substation. The
test equipment (150) is capable of administering the modified substation
data (simulation) to study response of devices, interactions between
various devices, and also performance of the substation devices including
performance of communication network devices (accessories). This
administering the modified data to perform the simulation of events in
fullest context concerning the target system is an exemplary feature of
the embodiment disclosed herein.

[0050] Administration of modified substation data in algorithmic manner
can include sending out data on the communication channel (140) and also
receiving data from the communication channel to algorithmically a)
decide further administration (sending and receiving) of data, b) carry
out verification/validation activities or c) draw conclusions.

[0051] As an example, administration for power system event simulation may
include the test equipment (150) to check the time taken for the sample
value packets from the server to target, where the time stamp information
from the source is compared with the time stamp from the target by the
test equipment as a part of simulation studies to estimate performance.
As another example, the CRC errors that indicate cable errors or errors
with network card are captured from the data in the communication channel
and inferred. The data may be used to infer if the errors are due to
local collision, remote collision or late collision. The test equipment
may directly acquire the desired information from the communication
channel or compute/estimate from the information acquired from the
communication channel and use them for comparison with known/expected
values/information (benchmark activity). Further examples for benchmark
in network condition simulations are: [0052] 1) Local collision if
found greater than 10% (benchmark value) are usually considered as an
issue with network. [0053] 2) CRC errors greater than 2% (benchmark
value) of traffic is considered excessive.

[0054] Examples from power system conditions for benchmark may include
performance of one kind of device (eg one manufacturer against another
manufacturer for IED devices), substation configurations (including
network configuration) with applications for monitoring, control or
protection or identification of exceptions from quality attributes for
IEC 61850-9-2 sampled values (overflow, out-of-range etc).

[0055] In another non exhaustive exemplary case, simulation of events with
relevance to refurbish or upgrading a system is considered. Accordingly,
the acquisition of data as described herein can be obtained from the
existing legacy substation. As explained earlier, inputs from the user
may also be included in combination thereto. In a legacy substation, it
is assumed that the merging unit is absent (e.g., the information
(analog) from CT/VT are directly provided to the IEDs and a centralized
disturbance recorder, if provided in the substation). The fault in any of
the feeders then is assumed to be stored in the IED associated with the
feeder where the fault has occurred. The centralized disturbance recorder
stores all the Bay currents and voltages corresponding to that power
system fault event. This stored disturbance data is acquired and made
available as a base station record along with the substation
configuration information. If the centralized disturbance recorder is not
available, then the data from the IED associated with the feeder where
the fault has occurred is acquired. This data can further be used to
reconstruct the entire substation data.

[0056] In case of simulation during an upgrade activity from legacy
substation system to an advanced substation system (with IEC 61850
compliant merging unit), the base substation record if created from the
legacy system using the stored disturbance data is made use or any other
relevant base substation record is used for simulation. The fault data
here is mapped to the merging unit and used for simulation of the fault
captured from a legacy system in the upgraded system. It is to be noted
that such simulation of faults from legacy system are possible in a new
or any different system.

[0057] In another embodiment, the test equipment is also provided with a
power system simulation component to create a virtual substation and
events through power system simulation in the virtual substation
contribute to substation condition data. Simulations in non-critical
cases, where performance related aspects are not the core aspect of study
or where non-real time studies are acceptable; the simulation is for
example carried out through appropriate administration with the data
obtained from power system simulation component in the virtual substation
executed in conjunction with simulation in target substation. For
critical cases where performance related aspect is simulated the
substation condition data from simulation in virtual substation may be
pre-recorded and available as a base station record. It is to be noted
that the data from the real substation (obtained from communication
channel) may also be used as an input for simulation in the virtual
substation. This feature can be useful to plan or design modification or
up-gradation in a substation.

[0058] It should also be noted that the embodiments as herein described
before are not exhaustive and various possible combinations can be
construed accordingly. The foregoing description sets forth numerous
specific details to convey a thorough understanding of embodiments of the
present disclosure. However, it will be apparent to one skilled in the
art that embodiments of the present disclosure may be practiced without
these specific details. Some well-known features are not described in
detail in order to avoid obscuring the present invention. Other
variations and embodiments are possible in light of above teachings, and
it is thus intended that the scope of the present disclosure not be
limited by this detailed description.

[0059] As such, it will be appreciated by those skilled in the art that
the present invention can be embodied in other specific forms without
departing from the spirit or essential characteristics thereof. The
presently disclosed embodiments are therefore considered in all respects
to be illustrative and not restricted. The scope of the invention is
indicated by the appended claims rather than the foregoing description
and all changes that come within the meaning and range and equivalence
thereof are intended to be embraced therein.